From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB78BC282C5 for ; Sat, 26 Jan 2019 07:55:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76991218A6 for ; Sat, 26 Jan 2019 07:55:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727694AbfAZHzQ (ORCPT ); Sat, 26 Jan 2019 02:55:16 -0500 Received: from www262.sakura.ne.jp ([202.181.97.72]:60939 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726122AbfAZHzP (ORCPT ); Sat, 26 Jan 2019 02:55:15 -0500 Received: from fsav102.sakura.ne.jp (fsav102.sakura.ne.jp [27.133.134.229]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x0Q7tD7O006811; Sat, 26 Jan 2019 16:55:13 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav102.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav102.sakura.ne.jp); Sat, 26 Jan 2019 16:55:13 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav102.sakura.ne.jp) Received: from [192.168.1.8] (softbank126126163036.bbtec.net [126.126.163.36]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id x0Q7tCD3006805 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NO); Sat, 26 Jan 2019 16:55:13 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: pids.current with invalid value for hours [5.0.0 rc3 git] From: Tetsuo Handa To: =?UTF-8?Q?Arkadiusz_Mi=c5=9bkiewicz?= Cc: Tejun Heo , cgroups@vger.kernel.org, Aleksa Sarai , Jay Kamat , Roman Gushchin , Michal Hocko , Johannes Weiner , linux-kernel@vger.kernel.org, Linus Torvalds References: <20190117122535.njcbqhlmzozdkncw@mikami> <1d36b181-cbaf-6694-1a31-2f7f55d15675@gmail.com> <96ef6615-a5df-30af-b4dc-417a18ca63f1@gmail.com> <1cdbef13-564d-61a6-95f4-579d2cad243d@gmail.com> <20190125163731.GJ50184@devbig004.ftw2.facebook.com> <480296c4-ed7a-3265-e84a-298e42a0f1d5@I-love.SAKURA.ne.jp> <6da6ca69-5a6e-a9f6-d091-f89a8488982a@gmail.com> <72aa8863-a534-b8df-6b9e-f69cf4dd5c4d@i-love.sakura.ne.jp> Message-ID: <33a07810-6dbc-36be-5bb6-a279773ccf69@i-love.sakura.ne.jp> Date: Sat, 26 Jan 2019 16:55:13 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <72aa8863-a534-b8df-6b9e-f69cf4dd5c4d@i-love.sakura.ne.jp> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/01/26 15:10, Tetsuo Handa wrote: > On 2019/01/26 11:41, Arkadiusz Miśkiewicz wrote: >> dmesg: >> http://ixion.pld-linux.org/~arekm/cgroup-oom-2.txt OK. There is a refcount leak bug in wake_oom_reaper() which became visible by enabling oom_group setting. static void wake_oom_reaper(struct task_struct *tsk) { /* tsk is already queued? */ if (tsk == oom_reaper_list || tsk->oom_reaper_list) return; get_task_struct(tsk); spin_lock(&oom_reaper_lock); tsk->oom_reaper_list = oom_reaper_list; oom_reaper_list = tsk; spin_unlock(&oom_reaper_lock); trace_wake_reaper(tsk->pid); wake_up(&oom_reaper_wait); } (1) oom_reaper_list and tsk(*)->oom_reaper_list are initially NULL. (2) Since tsk(2160) != oom_reaper_list && tsk(2160)->oom_reaper_list == NULL, get_task_struct(tsk(2160)) is called. (3) tsk(2160)->oom_reaper_list = oom_reaper_list (which is NULL). (4) oom_reaper_list = tsk(2160) (which is not NULL). (5) Since tsk(2150) != oom_reaper_list (which is tsk(2160)) && tsk(2150)->oom_reaper_list == NULL, get_task_struct(tsk(2150)) is called. (6) Step (5) repeats on tsk(2153, 2164. 2166, 2163, 2159, 2161, 2154). (7) Since tsk(2160) != oom_reaper_list (which is tsk(2154)) && tsk(2160)->oom_reaper_list == NULL (because it was NULL as of (2)), get_task_struct(tsk(2160)) is called again. (8) oom_reap_task() calls put_task_struct(tsk(2160)) for only once because tsk(2160) appears on the oom_reaper_list for only once; leaking refcount. Jan 26 03:33:49 xps kernel: Memory cgroup out of memory: Kill process 2160 (python3) score 66 or sacrifice child Jan 26 03:33:49 xps kernel: Killed process 2160 (python3) total-vm:272176kB, anon-rss:31668kB, file-rss:3248kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Tasks in /test_2149 are going to be killed due to memory.oom.group set Jan 26 03:33:49 xps kernel: Killed process 2150 (python3) total-vm:272176kB, anon-rss:27572kB, file-rss:3248kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2153 (python3) total-vm:261936kB, anon-rss:17396kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2164 (python3) total-vm:272176kB, anon-rss:27572kB, file-rss:3248kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2166 (python3) total-vm:261936kB, anon-rss:15088kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2163 (python3) total-vm:261936kB, anon-rss:21496kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2159 (python3) total-vm:282420kB, anon-rss:23944kB, file-rss:3128kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2161 (python3) total-vm:251692kB, anon-rss:11172kB, file-rss:3060kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2154 (python3) total-vm:261936kB, anon-rss:15084kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2160 (python3) total-vm:272176kB, anon-rss:31668kB, file-rss:3248kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2155 (python3) total-vm:261936kB, anon-rss:17364kB, file-rss:3056kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2168 (python3) total-vm:272176kB, anon-rss:29620kB, file-rss:3108kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2156 (python3) total-vm:251692kB, anon-rss:11204kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2157 (python3) total-vm:251692kB, anon-rss:11172kB, file-rss:3088kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2169 (python3) total-vm:261936kB, anon-rss:19448kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2158 (python3) total-vm:272176kB, anon-rss:23944kB, file-rss:3192kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2170 (python3) total-vm:251692kB, anon-rss:13252kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2171 (python3) total-vm:261936kB, anon-rss:17396kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2173 (python3) total-vm:251692kB, anon-rss:11204kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2152 (python3) total-vm:261936kB, anon-rss:13724kB, file-rss:3100kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2174 (python3) total-vm:251692kB, anon-rss:11160kB, file-rss:3120kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2172 (python3) total-vm:251692kB, anon-rss:9128kB, file-rss:3116kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2187 (python3) total-vm:261936kB, anon-rss:23516kB, file-rss:3116kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2184 (python3) total-vm:251692kB, anon-rss:13500kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2151 (python3) total-vm:251692kB, anon-rss:9108kB, file-rss:3096kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2182 (python3) total-vm:251692kB, anon-rss:12196kB, file-rss:3140kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2175 (python3) total-vm:261936kB, anon-rss:13996kB, file-rss:3124kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2183 (python3) total-vm:251692kB, anon-rss:9124kB, file-rss:3112kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2177 (python3) total-vm:251692kB, anon-rss:9148kB, file-rss:3140kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2186 (python3) total-vm:261936kB, anon-rss:15336kB, file-rss:3152kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2189 (python3) total-vm:251692kB, anon-rss:9156kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2178 (python3) total-vm:251692kB, anon-rss:11204kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2185 (python3) total-vm:261936kB, anon-rss:15084kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2190 (python3) total-vm:251692kB, anon-rss:11204kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2179 (python3) total-vm:251692kB, anon-rss:9156kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2180 (python3) total-vm:251692kB, anon-rss:5060kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2181 (python3) total-vm:261936kB, anon-rss:21492kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2176 (python3) total-vm:261936kB, anon-rss:15348kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2188 (python3) total-vm:251692kB, anon-rss:7108kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2191 (python3) total-vm:261936kB, anon-rss:14556kB, file-rss:3188kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: Killed process 2192 (python3) total-vm:241448kB, anon-rss:3456kB, file-rss:2712kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2163 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2192 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2191 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2188 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2176 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2181 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2180 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2179 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2190 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2185 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2178 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2189 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2186 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2177 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2175 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2182 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2151 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2184 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2187 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2172 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2174 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2173 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2171 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2158 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2169 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2157 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2156 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2168 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2155 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2160 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2154 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:49 xps kernel: oom_reaper: reaped process 2161 (python3), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB Jan 26 03:33:50 xps kernel: python3 invoked oom-killer: gfp_mask=0x6000c0(GFP_KERNEL), order=0, oom_score_adj=0 Jan 26 03:33:50 xps kernel: CPU: 1 PID: 2217 Comm: python3 Tainted: G E T 5.0.0-rc3-00104-gc04e2a780caf-dirty #289 Since we assumed that wake_oom_reaper() is called for only once for one out_of_memory() request, /* tsk is already queued? */ if (tsk == oom_reaper_list || tsk->oom_reaper_list) return; no longer works.